Image pickup apparatus having wireless transmitter-receiver unit

ABSTRACT

An image pickup apparatus is provided that is capable of avoiding an image pickup device and control system devices thereof from being affected by heat generated by a wireless transmitter-receiver unit, whereby the control system devices can stably be operated, while avoiding the quality of photographed image from being deteriorated. In the image pickup apparatus, a power unit has an upper limit of guaranteed temperature higher than that of the image pickup device and higher than those of an image processing unit and a control unit which are the control system devices, and is mounted on a mounting surface of a board together with the image processing unit and the control unit. A wireless transmitter-receiver unit is disposed parallel to and facing the mounting surface of the board so as to cover the power unit mounted on the board.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an image pickup apparatus that has awireless transmitter-receiver unit.

2. Description of the Related Art

Some image pickup apparatus has a wireless transmitter-receiver unitthat wirelessly transmits data of an image, which is picked up by animage pickup device such as a CCD sensor or a CMOS sensor, andwirelessly receives image data from outside. If heat generated by thewireless transmitter-receiver unit in operation is conveyed to the imagepickup device, the quality of picked-up image is deteriorated due to theinfluence of the heat.

In Japanese Laid-open Patent Publication No. 2005-79931, there isproposed a technique in which an image pickup device and a wirelesstransmitter-receiver unit are disposed away from each other to avoidheat generated by the wireless transmitter-receiver unit from beingconveyed to the image pickup device, thereby avoiding the quality ofpicked-up image from being deteriorated by the generated heat.

However, even if the heat generated by the wireless transmitter-receiverunit can be avoided from being conveyed to the image pickup device bythe technique disclosed in Japanese Laid-open Patent Publication No.2005-79931, there is a fear that the generated heat is conveyed tocontrol system devices such as an image processing unit and a controlunit. In that case, the control system devices are affected by the heatand become unstable in operation.

SUMMARY OF THE INVENTION

The present invention provides an image pickup apparatus capable ofavoiding an image pickup device and control system devices from beingaffected by heat generated by a wireless transmitter-receiver unit,thereby stably operating the control system devices, while avoiding thequality of photographed image from being deteriorated by the generatedheat.

According to one aspect of this invention, there is provided an imagepickup apparatus comprising an image pickup device configured tophotoelectrically convert an object image into image signals, an imageprocessing unit configured to perform image processing on the imagesignals output from the image pickup device, a control unit configuredto control the image pickup device and the image processing unit, apower unit configured to supply electric power to the image pickupdevice, the image processing unit, and the control unit, a board havinga mounting surface on which the image processing unit, the control unit,and the power unit are mounted, and a wireless transmitter-receiver unitconfigured to wirelessly transmit and receive image data, wherein thepower unit has heat resistance higher than those of the image pickupdevice, the image processing unit, and the control unit, and thewireless transmitter-receiver unit is disposed facing the mountingsurface of the board in such a manner that a distance between thewireless transmitter-receiver unit and the power unit becomes shorterthan a distance between the wireless transmitter-receiver unit and theimage pickup device, becomes shorter than a distance between thewireless transmitter-receiver unit and the image processing unit, andbecomes shorter than a distance between the wirelesstransmitter-receiver unit and the control unit.

With this invention, it is possible to avoid the image pickup device andcontrol system devices of the image pickup apparatus from being affectedby the heat generated by the wireless transmitter-receiver unit of theimage pickup apparatus, whereby the control system devices can stably beoperated, while avoiding the quality of photographed image from beingdeteriorated.

Further features of the present invention will become apparent from thefollowing description of an exemplary embodiment with reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing a control system of a digital videocamera, which is an example of an image pickup apparatus according toone embodiment of this invention;

FIG. 2 is an external perspective view of the digital video camera asseen from the rear of the camera;

FIG. 3 is an external perspective view showing a state where an imagedisplay unit of the digital video camera is open;

FIG. 4 is a perspective view of a main board of the camera;

FIG. 5 is a perspective view showing an example arrangement of the mainboard and a lens unit in the camera;

FIG. 6 is a perspective view showing a state where a wirelesstransmitter-receiver unit is connected to the main board;

FIG. 7 is a perspective view showing a positional relation between themain board and the image display unit; and

FIG. 8 is a flowchart showing a switch operation disabling processperformed by a control unit of the camera to make an ON-operation of awireless transmission reception ON/OFF switch ineffective.

DESCRIPTION OF THE EMBODIMENTS

The present invention will now be described in detail below withreference to the drawings showing a preferred embodiment thereof.

FIG. 1 shows, in block diagram, a control system of a digital videocamera, which is an example of an image pickup apparatus according toone embodiment of this invention.

As shown in FIG. 1, the digital video camera of this embodiment includesan image pickup device 104, which is comprised of, e.g., a CCD sensor ora CMOS sensor. An object image passing through a lens unit 112 is formedon the image pickup device 104 that photoelectrically converts theobject image into a series of analog image signals. Under the control ofa control unit 101, the analog image signals are output to an A/Dconverter 105.

The A/D converter 105 converts the analog image signals into digitalimage signals and outputs these signals to an image processing unit 106under the control of the control unit 101. In, e.g., a recording mode,the digital image signals are sequentially output from the A/D converter105 to an image display unit 108, and an image is displayed on the imagedisplay unit 108. The image display unit 108 functions as an electronicview finder or an LCD monitor.

The image processing unit 106 performs various image processing such asenlargement/reduction processing on the digital image signals suppliedfrom the A/D converter 105. In, e.g., image recording processing, thedigital image signals subjected to image processing are sequentiallyaccumulated into, e.g., a RAM (not shown). Then, the accumulated imagesignals are encoded, together with photographing time information andframe rate information, into moving image data of AVCHD format, and arerecorded into a recording medium 107.

Under the control of the control unit 101, the image processing unit 106reads and decodes the encoded moving image data recorded in therecording medium 107, and outputs the decoded moving image data to theimage display unit 108. Also, the image processing unit 106 performsimage processing on moving image data and on GUI data stored in a ROM102, synthesizes the processed moving image data and the processed GUIdata together, and outputs the synthesized data to the image displayunit 108.

An operation input unit 103 accepts a user operation input, and notifiesthe control unit 101 of a content of the operation input. The operationinput unit 103 includes, for example, a mode changeover switch 201,trigger switch 202, power ON/OFF switch 203, and wireless transmissionreception ON/OFF switch 204 (see FIGS. 2 and 3).

A wireless transmitter-receiver unit 109 performs processing forwireless transmission on moving image data or still image data stored inthe recording medium 107 or on picked-up image data, and transmits theprocessed image data via an antenna (not shown). The wirelesstransmitter-receiver unit 109 receives image data via the antenna,performs predetermined processing on the received image data, andoutputs the processed data to the image display unit 108. At image datatransmission and reception, the wireless transmitter-receiver unit 109sometimes generates heat and becomes high temperature.

A power unit 110 converts electric power supplied from each of a battery111 and an external power supply unit 209 into a predetermined voltage,and supplies the power of the predetermined voltage to respective partsof the camera.

The control unit 101 controls the entire camera. To this end, thecontrol unit 101 reads out a control program stored in, e.g., the ROM102, develops the control program on the RAM (not shown), and executesthe control program to thereby control operations of respective parts ofthe camera.

The control unit 101 and the image processing unit 106 (which arecontrol system devices of the camera) each have a low upper limit ofguaranteed temperature, and each become unstable in operation when theupper limit of guaranteed temperature is exceeded. When an upper limitof guaranteed temperature of the image pickup device 104 is exceeded,the quality of picked-up image tends to be deteriorated.

FIG. 2 shows in external perspective view the digital video camera asseen from a photographer's side (i.e., from the rear of the camera).FIG. 3 shows in external perspective view a state where the imagedisplay unit 108 of the digital video camera is open.

As shown in FIGS. 2 and 3, a grip belt 205 is provided on a right sidesurface of the camera body 100 as seen from the photographer's side. Thephotographer can hold the camera body 100 with one hand placed betweenthe camera body 100 and the grip belt 205. The image display unit 108 isopenably and closably provided on a left side surface of the camera body100 through a hinge 206. The image display unit 108 when closed isreceived in the left side surface of the camera body 100.

The mode changeover switch 201 and the power ON/OFF switch 203 areprovided on an upper surface of the camera body 100, and the triggerswitch 202, wireless transmission reception ON/OFF switch 204, externalpower supply unit 209, and battery 111 are provided on a rear surface ofthe camera body 100.

FIG. 4 shows in perspective view a main board 302, FIG. 5 shows inperspective view an example arrangement of the main board 302 and thelens unit 112, and FIG. 6 shows in perspective view a state where thewireless transmitter-receiver unit 109 is connected to the main board302. FIG. 7 shows a positional relation between the main board 302 andthe image display unit 108 in perspective view.

As shown in FIG. 4, the control unit 101, the image processing unit 106,and power inductors 301 of the power unit 110 are mounted on the mainboard 302. The main board 302 is disposed in the camera body 100 in sucha manner that the side of the main board 302 on which the powerinductors 301 are mounted (i.e., the left side of the main board 302 asseen in FIG. 4) faces the rear surface of the camera body 100. Thus, thepower inductors 301 are mounted near the external power supply unit 209and near the battery 111, whereby wirings between the power inductors301 and the external power supply unit 209 and between the powerinductors 301 and the battery 111 can be shortened in length.

The power inductors 301 have an upper limit of guaranteed temperaturehigher than those of the image pickup device 104, control unit 101, andimage processing unit 106. In other words, the power inductors 301 ofthe power unit 110 are higher in heat resistance than the image pickupdevice 104, control unit 101, and image processing unit 106. Inaddition, the power inductors 301 hardly become unstable in operation,even if the upper limit of guaranteed temperature is exceeded.

As shown in FIGS. 5 and 7, the main board 302 is disposed between thelens unit 112 and the left side surface of the camera body 100 andsubstantially parallel to the left side surface in which the imagedisplay unit 108 in the closed state is received. Thus, heat generatedin the main board 302 is hardly conveyed to the right side surface ofthe camera body 100 on which the grip belt 205 is provided. The mainboard 302 serving as a board of this invention has a mounting surfacethereof disposed on a side close to the lens unit 112. The mountingsurface of the main board 302 has a central portion thereof on which thecontrol unit 101 is mounted, a front-end side thereof (which is close tothe lens unit 112) on which the image processing unit 106 is mounted,and a rear-end side thereof on which the power inductors 301 aremounted.

Connectors 303, 304 are mounted on the main board 302. The connector 303is disposed between the power inductors 301 and the control unit 101.The connector 304 is disposed downward of the power inductors 301. Onthe rear-end side of the lens unit 112, a device board 307 on which theimage pickup device 104 is mounted is disposed to extend perpendicularto the main board 302.

The main board 302 is supplied with electric power from the battery 111or from the external power supply unit 209 through a flexible board (notshown) and the connector 303. The power supplied to the main board 302is converted into a predetermined voltage by the power unit 110 thatincludes the power inductors 301, and then the power of thepredetermined voltage is supplied to respective parts of the camera.Power to the wireless transmitter-receiver unit 109 is supplied via theconnector 304 and a flexible board 310 (see FIG. 6).

The wireless transmitter-receiver unit 109 is disposed substantiallyparallel to and facing the mounting surface of the main board 302 so asto be close to and so as to cover the power inductors 301 mounted on themain board 302. Thus, a distance between the transmitter-receiver unit109 and the power inductors 301 becomes shorter than a distance betweenthe transmitter-receiver unit 109 and the control unit 101, becomesshorter than a distance between the transmitter-receiver unit 109 andthe image processing unit 106, and becomes shorter than a distancebetween the transmitter-receiver unit 109 and the image pickup device104. In other words, among the component parts mounted on the main board302, the power inductors 301 having a high upper limit of guaranteedtemperature are most affected by the heating of the wirelesstransmitter-receiver unit 109.

In this embodiment, the operation mode of the camera can be switchedbetween a photographing mode and a playback mode by using the modechangeover switch 201. In the photographing mode, however, an amount ofheat generated by the power inductors 301 increases. When the wirelesstransmission reception ON/OFF switch 204 is turned on in thephotographing mode, the wireless transmitter-receiver unit 109 operatesand generates heat. Thus, there is a fear that the image pickup device104, control unit 101, and image processing unit 106, which are disposedaway from the wireless transmitter-receiver unit 109, are affected bythe heat generated by the power inductors 301 and by the wirelesstransmitter-receiver unit 109.

Accordingly, in this embodiment, the ON-operation of the wirelesstransmission reception ON/OFF switch 204 is made ineffective in thephotographing mode. To this end, the control unit 101 executes a switchoperation disabling process shown in FIG. 8.

In the switch operation disabling process of FIG. 8, the control unit101 determines based on a signal from the mode changeover switch 201whether the camera operates in the photographing mode (step S401). Whenthe camera operates in the photographing mode, the process proceeds tostep S402 where the control unit 101 makes the ON-operation of thewireless transmission reception ON/OFF switch 204 ineffective. On theother hand, when the camera does not operate in the photographing mode,the process proceeds to step S403 where the control unit 101 makes theON-operation of the wireless transmission reception ON/OFF switch 204effective.

Accordingly, in the photographing mode where the amount of heatgenerated by the power inductors 301 becomes large, the control unit 101performs control to cause the wireless transmitter-receiver unit 109 tobecome inoperable. It should be noted that in the photographing mode,the control unit 101 can perform control to stop the operation per se ofthe wireless transmitter-receiver unit 109 instead of making theON-operation of the wireless transmission reception ON/OFF switch 204ineffective.

As describe above, according to this embodiment, the distance betweenthe wireless transmitter-receiver unit 109 and the power inductors 301is made shorter than the distance between the transmitter-receiver unit109 and the control unit 101, is made shorter than the distance betweentransmitter-receiver unit 109 and the image processing unit 106, and ismade shorter than the distance between the transmitter-receiver unit 109and the image pickup device 104. On the other hand, the power inductors301 each have heat resistance higher than those of component parts ofthe image pickup device 104, and higher than those of component parts ofthe control system devices (such as the control unit 101 and the imageprocessing unit 106) of the video camera. Thus, the video camera is notbrought into an inoperable state, even if the power inductors 301 areaffected by the heating of the wireless transmitter-receiver unit 109.Furthermore, influences of heat generated by the wirelesstransmitter-receiver unit 109 on the image pickup device 104 and on thecontrol system devices can be reduced, whereby the control systemdevices can stably be operated while avoiding the quality ofphotographed image from being deteriorated.

While the present invention has been described with reference to anexemplary embodiment, it is to be understood that the invention is notlimited to the disclosed exemplary embodiment. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

This application claims the benefit of Japanese Patent Application No.2011-136219, filed Jun. 20, 2011, which is hereby incorporated byreference herein in its entirety.

1. An image pickup apparatus comprising: an image pickup deviceconfigured to photoelectrically convert an object image into imagesignals; an image processing unit configured to perform image processingon the image signals output from said image pickup device; a controlunit configured to control said image pickup device and said imageprocessing unit; a power unit configured to supply electric power tosaid image pickup device, said image processing unit, and said controlunit; a board having a mounting surface on which said image processingunit, said control unit, and said power unit are mounted; and a wirelesstransmitter-receiver unit configured to wirelessly transmit and receiveimage data, wherein said power unit has heat resistance higher thanthose of said image pickup device, said image processing unit, and saidcontrol unit, and said wireless transmitter-receiver unit is disposedfacing the mounting surface of said board in such a manner that adistance between said wireless transmitter-receiver unit and said powerunit becomes shorter than a distance between said wirelesstransmitter-receiver unit and said image pickup device, becomes shorterthan a distance between said wireless transmitter-receiver unit and saidimage processing unit, and becomes shorter than a distance between saidwireless transmitter-receiver unit and said control unit.
 2. The imagepickup apparatus according to claim 1, further including: a device boardon which said image pickup device is mounted, wherein said device boardis disposed to extend perpendicular to said board, and said wirelesstransmitter-receiver unit is disposed substantially parallel to andfacing the mounting surface of said board so as to cover said powerunit.
 3. The image pickup apparatus according to claim 1, furtherincluding: a lens unit configured to form the object image on said imagepickup device; and an image display unit configured to be openably andclosably provided on a side surface of said image pickup apparatus,wherein said board is disposed between said lens unit and the sidesurface of said image pickup apparatus.
 4. The image pickup apparatusaccording to claim 1, further including: a mode changeover switchconfigured to switch an operation mode of the image pickup apparatusbetween a photographing mode and a playback mode, wherein in a casewhere said control unit determines, based on a signal from said modechangeover switch, that the image pickup apparatus operates in thephotographing mode, said control unit controls said wirelesstransmitter-receiver unit such that said wireless transmitter-receiverdoes not operate.
 5. The image pickup apparatus according to claim 4,further including: a wireless transmission reception ON/OFF switchconfigured to be ON-OFF operated, wherein in a case where said controlunit determines that the image pickup apparatus operates in thephotographing mode, said control unit makes an ON-operation of thewireless transmission reception ON/OFF switch ineffective.